Known Issues with Some Clients

12.2 client does not support OCI_ATTR_SPOOL_MAX_USE_SESSION and thus SessionPool's session_max_use_count and set_session_max_use_count will fail on it with ORA-24315: illegal attribute type.

19.15 and all later clients do not return current schema (via Session::current_schema) until it is explicitly set via Session::set_current_schema. Session::current_schema works as expected in 19.13 client.

21c clients (at least with 19.3 database) is strangely picky about names of parameter placeholders for LOB columns. For example, if a table was created with the following LOB column:

CREATE TABLE table_with_lob (
    id   NUMBER GENERATED ALWAYS AS IDENTITY,
    txt  CLOB
);

and if an SQL parameter name is the same as the LOB column name (as in this example):

let stmt = session.prepare("
    INSERT INTO table_with_lob (txt) VALUES (:TXT) RETURNING id INTO :ID
")?;

Then 21c clients will fail executing this SQL with ORA-03120: two-task conversion routine: integer overflow. Renaming the parameter placeholder resolves this:

let stmt = session.prepare("
    INSERT INTO table_with_lob (txt) VALUES (:NEW_TXT) RETURNING id INTO :ID
")?;

21c clients also do not "like" some specific parameter names like :NAME which makes it fail with the same ORA-03120.

Note that 12.2 through 19.18 clients (as far as Sibyl's tests showed) do not exhibit this issue.

21c clients (at least when connected to the 19.3 database) cannot read LOBs piece-wize - something bad happens while it reads the very last byte of the last piece and the execution is aborted with SIGSEGV. Notably, they have no problem reading the second to last piece even if it has all the bytes but the very last one. Subsequently, an attempt to read the last one-byte piece gets aborted with memory violation.

All tested clients behave erratically in nonblocking mode when they execute piece-wize LOB operations. Therefore, in nonblocking mode Sibyl does not support LOBs piece-wise reading and writing.